I NEVER get tired of singing because I absolutely LOVE to sing! Unfortunately, my love for singing far outweighs my talent for singing... lol. I'm not what you'd call a "true singer," but I truly love to sing.
I sing in the shower, in the bed, in the car, walking the dog... I sing along with every commercial jingle on TV, on the radio, or anywhere else... I LOVE TO SING and I never get tired of it. One of the things I miss most about being active in church is singing on the praise team and in the choir. Even when we had two rehearsals per week and had to minister at 3 services, I still never got tired of singing.